This invention relates generally to a disposable diaper being elastically stretchable around a wearer's legs.
U.S. Pat. No. 4,695,278 discloses a disposable diaper provided with a pair of elastically stretchable leg-gasket cuffs and a pair of elastically stretchable barrier cuffs extending from a crotch region into front and rear waist regions of the diaper. In this known diaper art, the gasket cuffs are formed by bonding together respective portions of a liquid-permeable topsheet and a liquid-impermeable backsheet covering upper and lower surfaces of a liquid-absorbent core, respectively, which extend outward beyond transversely opposite side edges of the absorbent core. A portion of each gasket cuff lying in the crotch region is provided with elastic members disposed between the topsheet and the backsheet and bonded to an inner surface of at least one of these sheets in longitudinally stretched conditions. Each of the barrier cuffs is formed by bonding a narrow piece of sheet extending longitudinally of the diaper along its portion extending inboard of the elastic members for the leg-gasket cuff to an upper surface of the topsheet or by curving upward in an inverted U-shape the portion of the topsheet extending outward beyond the side edge of the absorbent core inboard of the elastic members for the leg-gasket cuff.
In the above-mentioned diaper, each of the leg-gasket cuffs is formed by bonding the liquid-permeable topsheet to the liquid-impermeable backsheet made of plastic film. The gasket cuff made of the liquid-permeable topsheet alone would provide a comfortable touch but would be of insufficient strength. In addition, it would be difficult for such gasket cuff to prevent body fluids from leaking around a wearer's leg. The gasket cuff made of the liquid-impermeable backsheet in the form of plastic film alone, on the other hand, would have insufficient air-permeability even though it may be possible for such a gasket cuff to alleviate leakage of body fluids. The gasket cuff made of the topsheet and the backsheet bonded together certainly eliminates many of these problems but insufficient air-permeability remains a problem to be solved.